PHmeter

Microprocessor Conductivity Meter Thermometer

Model HD 8706 is a precise instrument for measuring the electric conductivity of liquids and their temperature.

In conductivity measurements, the compensation of the temperature coefficient a Tis automatic with a Tvariable between 0.00%/°C and 4%/°C. The instrument is supplied complete with a conductimetry cell with 4 graphite electrodes (to eliminate polarization effects) and a built-in temperature sensor.

The possible range of measurement of this cell is extremely wide, from a few microsiemens (distilled water) to a fraction of Siemens (base or strong acid).

HD8706 complete kit

The instrument is provided with the following functions: “Autorange”, “Hold”, manual and/or automatic calibration with a sample solution (generally solutions of KCI with a known concentration) relative measurements, simultaneous storage (RCD) of minimum and maximum for both conductivity and temperature, Auto-Power-Off (it may be disabled), “Beep” to indicate that a key has been activated. The TP 870 range of probes is available for temperature measurements in a wider range than possible with the conductimetry cell.

Instrument Control Legenda

Input A DIN 8-pole connector. This input is suitable for the combined conductivity / temperature probe and for the TP 870 series of solely temperature probes.

HOLDsymbol indicating HOLD status.

Display.

MINsymbol. The value indicated on the display is the MIN value stored by the instrument.

MAXsymbol. The value indicated on the display is the MAX value stored by the instrument.

RCDsymbol. Indicates that the instrument is storing the maximum and minimum value of the probe inserted in input A.

HOLDkey. When this key is pressed the reading on the display is held while internally the instrument continues to update data.

RECkey. when this key is pressed the instrument is set to store che MAX, MIN and present values read at the probe input.

RELkey. For selecting REL relative operating mode. The relative measurement is taken with respect to the moment the REL key is pressed.

“aT” Key.When this key is pressed the modification of the temperature coefficient by means of the “triangle up-down” keys is enabled.

°C/°F Key. When this key is pressed temperature reading in °C or °F is selected.

“Triangle Up” key. This key is used during calibration to increase the value indicated on the display .

°C symbol, indicates that the reading being made is in °C.

°F symbol, indicates that the reading being made is in °F.

µS symbol, indicates that the reading being made is in µS (microSiemens).

mS symbol, indicates that the reading being made is in mS (milliSiemens).

REL symbol, indicates that a REL relative measurement is being taken.

B, flashing symbol, indicates that AUTO-POWER-OFF is disabled.

ON/OFF key ot switching the instrument on and off.

DATA-CALL key; when this key is pressed the display shows in sequence the MAX, MIN and present value of the signal detected by the probe inserted in input A.

XKeywhen this key is pressed the electric conductivity of the liquid being tested is measured .

CAL key when this key is pressed during the conductivity measurement, automatic and/or manual calibration is enabled.

Key V this key is used during calibration to decrease the value indicated on the display.

For measuring pH, mV and °C

The HD 8602 is a combined instrument for measuring pH, mV and °C in the laboratory, in the field and in industrial plants.

The instrument is provided with a BNC connector for pH electrodes, electrodes for measuring redox potential (ORP) or specific ion electrodes (ISE). A socket for 0 4 mm banana plugs is provided for connecting a reference electrode independent of the measuring electrode.

Compared to a cable that cannot be detached from the instrument, the BNC offers the advantage of being able to use all the electrodes available on the market an especially those types which for cost reasons do not have a connector directly on the electrode. Furthermore, with the BNC connector it is possible to disconnect the pH measuring cable (ORP, ISE), so that temperature can be measured alone without the electrode connecting cable getting in the way.

The STS 4 temperature measuring probe is optional and is connected to the instrument by means of a 5-pole DIN connector. During pH measurements this probe automatically compensates the electrode temperature compensates the electrode temperature coefficient. If the temperature sensor is not connected, the temperature coefficient may be compensated manually. A mechanical push-button panel protected by a polycarbonate membrane offers the possibility of selecting the desired unit (pH, mV or °C).

Adjustment of asymmetry ( ~0> pH) and ( z slope) in pH measurements is also carried out on the push-button panel. During the calibration phase (CAL) the symbols on the display flash. To return to the measuring mode, push the CAL button again. The calibration data are memorized event when the instrument is turned off. When the HOLD button is pressed the reading on the display is blocked; when the HOLD button is pressed for the second time the instrument returns to normal operation (continuous updating of the reading). To turn the instrument off, press the OFF button.

The instrument will also turn itself off automatically after about 3 minutes if it is in the measuring mode. In the HOLD and calibration modes the instrument will not turn itself off. Automatic cut-off in the measuring mode may be avoided by shifting the jumper in the battery compartment.